SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47baf49fe03fb1b84dd4ba679e6485264ba4568d3158d061623d991255e152cf' 
  AND token = 'mjqaxHJY8KhoqL1VdftR/pJIE3gOeRShBxso/zQoPFs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}